Whole Object Name
Ganymede Scale Model
Scale model of Jupiter’s moon Ganymede. It is a 1:100,000,000 scale model, based on an estimate of Ganymede’s diameter to be 5,265 kilometres. Ganymede was first discovered by Italian astronomer Galileo Galilei and is one of Jupiter's four largest moons. Named after their discoverer, the Galilean moons consist of Ganymede, Callisto, Io and Europa in descending size order.
Ganymede is the largest of Jupiter's moons and is also the largest moon in the Solar System - larger even than the planet Mercury. It has a metallic iron core covered in a rocky shell, on top of which is a thick layer of ice. Studies of Ganymede done with the Hubble Space Telescope in 2015 suggest that the giant moon also has a subsurface salt-water ocean, containing more liquid water than is found on Earth.
Like all of the Galilean moons, Ganymede is named after a lover of Zeus - Zeus being the Greek equivalent of the Roman god Jupiter. Johannes Kepler suggested the naming system to Simon Marius who published the four names in his Mundus Jovialis, published in 1614. Marius had discovered the four moons around the same time as, and independently of, Galileo. It took until the twentieth century for these mythologically themed names to be widely adopted, with many other alternatives offered over the years - including Galileo's own suggestions.